Power transmitting device for overhead garage doors



1386- 1953 J. H. GRENZEBACK POWER TRANSMITTING DEVICE FOR OVERHEAD GARAGE DOORS 2 Sheets-Sheet 1 Filed Dec. 20, 1949 INVENTOR.

J4ME$ f]. Gan/258A Cid 1953 J. H. GRENZEBACK 2,663,047'

POWER TRANSMITTING DEVICE FOR OVERHEAD GARAGE DOORS Filed Dec. 20, 1949 2 Sheets-Sheet 2 I N V EN TOR. (7 54455 H GIQENZEBA cz cent the top of the door frame.

of the type here considered may vary in width Patented Dec. 22 1953 UNITED POWER TRANSMITTING DEVICE FOR OVERHEAD GARAGE DOORS James H. Grenzeback, Los Angeles, Calif. Application December 20, 1949, Serial No. 134,012

This invention relates to overhead garage door construction and. operation and more particularly to a novel power transmission device for use with such doors.

Overhead type garage doors usually include a rigid panel cooperable with a garage door frame and are characterized by a method of operation which includes moving the rigid panel door into an overhead horizontal plane by rotation about a pivotal axis, the door extending within the garage in proximity to the top of thedoor frame. In some instances, in overhead position, an edge of the door may project beyond the vertical plane of the door frame. While traversing thefront portion of the garage, when being raised to an overhead horizontal position, the operation of some overhead garage'doors may interfere with vehicles having relatively high bodies, such as station wagons, 7

Various means have been provided for facilitating and controlling the moving of such an overhead type garage door from a vertical position to an overhead horizontal position. Prior proposed means have included various complicated and intricate arrangements of hardware and hardware accessories mounted on the side of the door frame or in an overhead position adja- Garage doors from 7 feet to 16 feet and larger, and are ofconsiderable weight. Although springs have been used for the purpose of counterbalancing the doors, prior arrangements have not been entirely satisfactory in that the weight has not been properly counterbalanced in all positions of a door. When a door is being lowered, it should drop slowly and reach a fully closed position without excessive impact; when it is being opened, very little effort should be exerted to initiate raising of the door but since the door (in its last stages of movement into fully open position) moves in a substantially horizontal plane, excessive counterbalancing is not needed at such stage. Ordinarily overhead garage door arrangements open and close the doors with unnecessary and undesirable impact at the initial and final positions.

These prior proposed means required a very careful and accurate installation in order to permit the door to properly operate and to provide adequate control of the door during its movement from vertical to horizontal position.

The primary object of this invention is to design and provide a power transmission device cooperable with overhead type garage doors wherein opening and closing of said doors is facili- 2 Claims. (01. 161) tated, the hardware accessories used in connection with the power transmitting device are easily installed and adapted to a door frame, and the power transmitting device is simple and compact to afford economy of space within the garage.

Another object of this invention is to provide an overhead garage door construction and operation wherein relatively small and light springs are used to partially counterbalance the door.

A further object of this invention is to provide an overhead garage door construction and operation wherein the door may b moved into and from open overhead position by applying a minimum of force, and yet so controlled a to obtain a smooth, uniform action throughout movement of the door.

This invention contemplates a power transmitting device for use on overheard garage doors of rigid, panel type wherein counterbalancing means may be adaptable for installation adjacent to either the top or bottom of the door frame to conserve storage space and to minimize interference of the door construction with utilization of the garage.

Generally speaking, this invention contemplates at power transmitting device for overhead garage doors of the rigid panel type wherein a garage door may be pivotally hung at opposite sides from approximately the mid-point of a door frame for movement about a horizontal axis, parallel to and spaced from the plane of the door frame. The power transmitting device includes a member pivoted about the same axis as the door and connected to the door by a rigid lifting arm fixed at one end to the member at a point spaced from the pivotal axis and pivotally connected at the other end to the door. The member is provided with a marginal edge contoured to provide points lying at varying distances from the pivotal axis of the member. Flexible means extending along and in contact with said marginal edge may be secured to the member at one end and at the other end connected to a counterbalancing spring means which may be suitably anchored adjacent either the top or bottom of the door frame. The marginal edge of the power transmitting member is so contoured that the resultant eifect of the spring means and the several leverages provided by the member, as measured from the pivotal axis to the several points on the marginal edge of the member, provides a smooth, uniform action when the garage door is moved from a vertical position to an overhead horizontal position.

Other objects and advantages of this invenaxis of lifting arm does not cross the axis of pivot [9, but instead is spaced therefrom a distance X (Fig. 3).

The manner of operationof the power trans- 'mitting device embodied in the arangement of the cam member 26, lifting arm 25 and spring means will be evident from the operation of the door. In normal closed position, as shown in Fig. 1, wherein the door l4 lies in a vertical plane and is supported by the roller means 32 and from the bracket l5 through the pivotal axis of the member 20 and lifting arm 25, the spring'means 35 is in its maximum extended position for partially counterbalancing the weight of the door It and is exerting its maximum counterbalancing force. It should be noted, in this closed position,

that the flexible element departs themarginal edge of cam member 29 and is extended downwardly to spring 35 in a plane slightly converging with respect to the vertical plane of the door.

the fixed connection of the lifting arm to the member 26 and extending on one side of the pivotal axis of the cam member. The moment of force exerted by the weight of the door about the pivotal axis in this closed position has a short moment arm, virtually the distance between the pivotal axis and the vertical plane of the door.

A stop 4!! may be provided for positioning the 'doorand limiting its movement to a vertical closed position.

As a slight force is applied to the bottom of the door to move the door to an overhead horizontal position, movement of the door will cause turning of member 20 about its pivotal axis. Since the spring means 35 exerts a force which is proportional to the amount of its deflection, the decrease in spring counterbalancing forces upon contraction of the sp g, is compensated for by the change in point of contact of the flexible element 36 with the marginal edge 34, due to turning of the member about the pivotal axis for increasing the effective leverage.

From the closed vertical position of the door and to a position of the door in a plane lying at 45 to the vertical, the moment force of the door increases to a maximum. During movement of the door to a 45 position, the counterbalancing effect of the spring is decreased by contraction thereof while the points of contact provided on the marginal edge for the flexible member are spaced an increasing distance from the pivotal axis, thus providing increasing leverages which not only compensate for thedecreased counterbalancing effect of the spring meansbut also for the increasing moment of force of the door.

When the door is lying in a plane of approximately 45 to the vertical wherein the moment of force of the door about the pivotal axis is the greatest, the member 29 is tangentially contacted by the flexible element at a point on the marginal edge of member Ell spaced 9, maximum distancefrom the pivotal axis of the member. This point, aifording maximum leverage, lies in a zone between a plane passing through the pivotal axis of the member and substantially parallel to the axis of the lifting arm and a parallel plane pass- 6 1 ing through the longitudinal axis of the liftin arm.

As the door is raised above the halfway position at 45, the moment of force of the door about the pivotal axis decreases. The distance of points of contact on the marginal edge 31; to the pivotal axis of the member is also selectively decreased in accordance With the change in length of the moment arm of the door and with the proportional contraction of the spring means 35 so as to provide easy, smooth operation of the door in its final movement-to horizontal position.

Thus it will be readily apparent that the contour of the marginal edge 34 of member as provides a plurality of points so spaced from the fixed pivotal axis of the member and door so as to afford various leverages related to the moment arm of the door and force exerted by the spring means to uniformly counterbalance movement of the door in all positions of the door as it is moved from a vertical to an overhead horizontal position.

It will be noted that when the door is in overhead open position the moment force of the weight of the door is acting to the left of the horizontal axis as viewed in Fig. 3. The spring 35 is under some tension and is not completely collapsed and a final or ultimate moment arm is made available by the member 26 whereby the spring forces act to positively urge and maintain the door in open overhead position. In other words, a small force is acting upon the bottom portion of the door through the lifting arm 25 in order to prevent the door in overhead position from closing unexpectedly.

In the modification illustrated in Fig. 5, the power transmitting device embodying this invention is so arranged as to permit anchoring the counterbalancing spring means adjacent the top of the door in order to position the spring means out of possible interference with use of the garage. In this'modifioation a door 50 is supported by roller and track assemblies generally indicated at 5| adjacent the top of the door and from a fixed pivotal axis 52 provided by a bracket 53 and a cam-shaped member as as in the previous modification. The member 54 is connected to the door by means of a lifting arm 55 pivotally connected to the lower portion of the door and having an end 5% fixed to the mem ber 54 as by welding at a point radially spaced from the pivotal axis 52 and between the point of initial tangential contact of a flexible element 5'! with a contoured marginal edge as of member 54 when the door is in vertical position.

It should be noted that the contoured marginal edge 58 is substantially identical in configuration as that described in the previous modification and that the member 5&- has been in effect reversed in position, as by turning it over about both its vertical and horizontal axes and then fixing end 56 of the lifting arm to the member at point lying between the pivotal axis and the tangential point of contact with the element 5?. The element 57 is suitably secured'at one end 59 to the member 5 and is suitably connected at to to an end of spring means ii! which may be conveniently anchored to a structural member of the garage adjacent the top of the door, as indicated at 62. The flexible element 5'! extends along and in contact with the marginal edge 58 from its point of connection to the memberto its point of separation for connection to the spring means 6! as in the previous modification.

aces-p47 It will be readily apparent that the method of operation of the modification shown in Fig; 4, is virtually the same as that described'in the previous modification, whereby as the door is moved from its vertical position the spring ti and the leverages afforded by the variable distances between the fixed pivotal axis of the member and the point of contact of the flexible element virtually oounterbalances the moment of the door about pivotal axis. As in the previous modification, the maximum moment of the door occus at virtually a halfway point when the door is lying in a plane of 45 and wherein the point of contact of the flexible element is at a p t on the marginal edge which is spaced a xiinum distance from the pivotal axis of t. e member to thereby afford a maximum counterbalancing leverage.

It will be readily apparent from the above description of the we modifications illustrated that the power transmitting device, including the cam-shaped n nbers and may be suitably designed so that the various leverages afforded by the marginal of the cam-shaped members will provide desired control of the door in its movement from a vertical position to an overhead horizontal position. For example, it may be desire in operation of the door, to provide several points in its upward movement wherein the door and the counterbalancing spring means 2i may be substantially in balance so that a garage door may be left in partially opened position. Such operation may be accomplished by providing a point on the marginal edge 3% in which the leverage afforded. by the distance between said point and pivotal of such member together with the counterbalancing action the spring will provide a counterbah ancing force equivalent to the movement of force of the door about the pivotal axis when the door is in the selected position.

When the is in open, overhead. horizontal position, the spring means and the member 23 are so arranged as to exert a slight counterbalancing force upon the door. It will be readily seen in 2, that the effect of this counterbalancing force when the door is in open position to maintain he door in open position without auizil' .ry ing or holding means. If desired, rela .4313 shallow recesses may be provided adjacent the inner ends of the track 33 for accommodating the roller 32 to define the proper cos-n position of the door.

In 010. g the -e by movement of the door from its o n horizonta position to ver tical position v the door downward movement of the door is resisted the effect of the counterbalancing forces exerted the spring 35 and the c In member 2%. The movement of the door about its pivotal is thus retarded and controlled so that the door will not rapidly fall or slam into its closed position. I

While the door is normally raised to overhead position by the manual. application of force to the bottom of the door, it is understood that electrioally actuated be employed to raise and to close the door as indicated in Fig. 6. The door actuating means includes a circular toothed sprocket as fixed to the inner surface of the member 2% for rotation about the pivotal axis by any suitable means such as welding or bolt and nut assemblies Since the rotation of the member 28 is approximately 180", a segment of a circular sprocket may be used instead of the circular sprocket illustrated. iThe teeth of the sprocket 65 mesh with the teeth of a pinion'gear 6i driven by a reversible electric motor 63, the motor 63 being supported from the bracket 55. Operation of the motor 63 by means of a suitable reversing switch (not shown) will cause the pinion gear 57 to drive the sprocket wheel 65 and the member 20 about the pivotal axis of the member and thus cause opening or closing of the garage door.

A different modification of the power transmitting device is illustrated in Figs. '7 to 10 inclusive. This modification differs from the previously described embodiments in that the flexible element is adjustably connected to the contoured member, the spring means is provided with a connection to a roller and track assembly, and the contoured member and flexible element are arranged for cooperation in a different manner.

A, garage, generally indicated at is provided with, a garage door opening l'l defined by an upstanding door .iamb l2 and a horizontal lintel I. A garage door M is ri vably supported within the door opening "l! by means including roller and track assemblies it each comprising a suitable channel-shaped track. member l5 secured to the garage in virtually horizontal position and extending rearwardly into the garage from the door opening. A roller 'i'a" c-ooperable with member 76 may be pivotally connected to a link '58 which is pivotally connected to an upper corner of the door.

The door M is pivotally mounted at each about a horizontal axis spaced rearv= rdly from the plane of the door by a bracket it secured to the door jamb '32. The bracket 1.. ovided with an aperture through which extends a 89 for pivotally mounting a contoured 1:0. 8i about the pivotal axis. Spacer washers may be provided on opposite sides of the contoured member 8 i.

The contoured member 8! is connected to the door by means of a lifting arm 35 having one end pivotally connected as at 84 to a bottom portion of the door. The other end of the arm as by welding to the contoured member 8! a point or area 35 radially spaced from the axis. It should be noted that the lifting arm 53 is provided with an offset portion adjacent its fixed connection to the contoured member so that the arm may travel in a vertical plane spaced inwardly from and parallel to the door jamb when the door is being opened close... for permitting mounting of the bracket id and the cam member 8| behind the door and spaces. away from the door opening. The bracket will alTord full utilization. of the door opening 1 that portion. of the garage immediately adjacent to the door opening.

The contoured mber Si is provid d with peripheral edge of irregular configura on hav spaced convex portions ti and and. inter-med ate depressions or concave portions viding spaced points along said o. distances from the pivotal axis of the member In this modification the contoured ins-lobe; preferably made of a single, fiat metal p Adjustably connected to the contoured in toured member isiprovided with a plurality of spacedyports QS adjacentto and along its contoured edge for selective reception of pi --92 of thelast link of the flexible element. The flexible element may be thus adjustably connected'to the contoured member in a plurality of selected difierent positions whereby the pins of the adjacent links may be moved alongthe edge of the contoured member for causing their contact thereterbalancing forces .1 Fieldadjustme-nt of effective counterbalancing forces is thus conveniently; 15.

provided. in order to obtain a desired lifting and closing action of the door.

The other end of the flexible element 9b is connected to a spring means 9% by any convenient means shown here as connecting rods 35. The spring means it is provided with a hook 95 which may be hung over track means it vat a suitable point spaced rearwardly from the plane of the door. The hook is not restrained against movement along track means it, but when once positioned the tension of the spring means 94 will hold the hook in place. When the door is in upper position, fine adjustment of spring tension may be made by slidably' moving the hook along the track means.

It should be particularly noted that the length of spring used in this modification is relatively short and of smaller diameter as compared with springs employed in the prior modifications.

The operation of the garage door construction shown in this modification is substantially similar to that described in the previous modifications. It will be noted from a consideration of Fig. 7 that when the door is in closed position the pins of the chain link contact points on the contoured member whereby the effective leverage, together with the action of the extended spring means 94, is virtually suiiicient to counterbalance the weight of the door. .As the door is moved from its vertical position the pins on the chain link contact spaced points on the contoured member at a greater distance from the pivotal axis of the member to provide a greater effective leverage. The maximum eiifective leverage indicated by the distance Y is available for counterbalancing the weight of the door by the contact of pins 92 immediately adjacent points spaced the maximum distance from the pivotal axis. As

' the door moves into overhead, horizontal position, the leverage effect of the contoured memleer is decreased so that the door may come to rest without an abrupt stop.

The contact of the pins of the chain link may be so adjusted as to cause either their spaced contact on convex portions 87 and 89 formed on the countoured member or in the depressions formed therebetween. It will thus be obvious that a large variation in the effective leverage provided by the contoured member is made available by selectively connecting the end link and pin of element St to a selected port 93.

It should be particularly noted that operation of a garage door embodying the power transmitting device described above will give a smooth, uniform movement of the door during both opening and closing of the door. Such uniform action is particularly desirable and facilitates control of the door when opened or closed.

In the operation of an overhead type garage door described above, the cam type member may turn through approximately 180 while the door- ,moves through onlyvirtually 90. v connection of the end of the lifting arm with v The pivotal the lower portion of the door 'permits'such operation and results inthe general vertically positioning of the arm when the door is in virtually overhead horizontal position. The distance to i which the bottom margin of the door may project beyond the lintel of the door frame when the door isin overhead position-may be determined by selection of the point of pivotal connection of the rigid lever arm with the cloor.

It will thus be readily apparent that the overhead type garage door constructionand operation describedyis simply constructed, is efiective for providing any desired type of door operation, and utilizes hardware accessories which are readily adaptable to a garage door frame.

The construction described above also provides a compact garage door operating mechanism or power transmitting device which occupies a minimum of space within the garage and which will not interlere with high bodied vehicles parked immediately adjacent the garage door opening.

It Will be understood by those skilled in the art that various modin'catlons and changes may be made in the embodiments of the invention described and illustrated above and all such changes coming within the scope of the appended claims are embraced thereby.

I claim:

1. In a power transmitting means for an overhead garage door construction guided at its upper end by virtually horizontal track means, the combinatlon of: a fiat member provided with means for pivotally mounting a door to be raised upon an axis parallel to the plane of the door and opposite the central portion of the door when in vertical position; a lifting arm having one end adapted to be pivotally connected to the door and having the other end rigidly connected to said member; said member having a contoured edge provided with convex and concave portions spaced at varying distances from the pivotal axis; a flexible element including spaced parallel links and pins connecting said links, said pins contacting the contoured edge at spaced points, the portion of said edge between the spaced points being accommodated between the spaced links; means for adjustably connecting one end of the flexible element along the edge of the member; spring means connected to the other end of the flexible element; means for connecting the spring means to the track means; said member and said spring means being cooperable for counterbalancing the weight of the door by the varying leverages made available by spaced contact of the flexible element with the edge of said member; the adjustable connection of the flexible element to the member being adapted to vary the points of spaced contact 01' the pins with the contoured edge for modifying the magnitude of counterbalancing i'orces effective during opening and closing of the door.

2. In a power transmitting means for overhead garage door construction guided at its upper end by virtually horizontal track means, the combination of: a member provided with means for pivotally mounting a door to be raised upon an axis parallel to the plane of the door; a lifting arm having one end adapted to be pivotally connected to a lower portion of the door and the other end rigidly connected to said member for movement with said. member in a plane transverse of the pivotal axis, said member being provided with a contoured edge including points,

therealong spaced at varying distances from the pivotal axis; a flexible element lying along said edge in contact with spaced points thereon and having one end secured to said member; a spring means under tension connected at one end to the other end of said flexible element, said memher and said spring means being cooperable for counterbalancing the weight of the door throughout movement of the door from a vertical to an overhead horizontal position through the varying leverages available by spaced contact of the flexible element with the edge of said memher; said spring means being provided at its other end with a connector means for frictionally engaging and for adjustable sliding along said track means for securing said other end of said spring means.

JAMES H. GRENZEBACK.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,214,229 Frasch Sept. 10, 1940 10 2,316,510 Ferris et a1 Apr. 13, 1943 FOREIGN PATENTS Number Country Date 51,864 Denmark July 13, 1936 15 

